Two types of small and thin circuit cards are in wide use, that each have an embedded integrated circuit to store data and that each have an active face with contact pads that are connected to the integrated circuit. One type is called a smart card that is standardized in two formats, the smaller of which is called a MICROSIM card which has contact pads arranged in two rows. Another type of card is the MMC (MultiMediaCard) which is sold by San Disk Company. The MMC card is somewhat similar in shape and size to the MICROSIM Card, with both having a cut corner forming a polarizing part that assures proper orientation of the card. The MMC card is of somewhat greater thickness, length, and width than the MICROSIM card, and has its contact pads arranged in a single row along one end of the card. The MICROSIM card is commonly used to identify the user for access to a telephone or other electronic system. The MMC card is commonly used to store larger amounts of data, and is commonly called a xe2x80x9cflashxe2x80x9d type card.
It is desirable to enable a single compact connector to make connections with at least two different types of circuit cards, of the type that have active faces with contact pads. In one application, a MICROSIM card may be used to identity the user, while an MMC card stores large quantity of data. In other applications, connections may be made to only one card at a time, but the connector should be able to receive and connect to the pads of at least two different types of circuit cards. The connector is commonly mounted on a circuit board, and should have a minimum size.
In accordance with one embodiment of the present invention, an electrical connector is provided for making electrical connections with contact pads on the active faces of thin and flat circuit cards, wherein the connector can connect to a plurality of circuit cards, and connect to them simultaneously, in a compact connector. The connector includes an insulative body with first and second sets of contacts arranged in first and second contact pad patterns corresponding to the patterns of contact pads on the circuit cards. A card-holder unit has first and second card-holding compartments for each holding a circuit card. The compartments hold the cards in parallel planes. The card-holder unit can be moved into a fully installed position on the body, wherein each set of contacts on the body engages pads on the active face of each card in the unit.
In one connector, the body has an upwardly-facing first card-engaging wall that lies at a first level and with the first set of contacts lying at that first wall. The body has a downwardly-facing second card-engaging wall that lies at a higher level than the first card-engaging wall. The cards are mounted on the card-holder unit with the lower card having its active face facing downwardly and with the upper card having its active face facing upwardly. The card-holder unit is slid into position between the upwardly-facing wall and downwardly-facing wall, with the pads of both cards engaged by corresponding sets of contacts.
In another arrangement, the first card-engaging wall faces upwardly and a second card-engaging wall also faces upwardly and lies at a higher level than the first wall. The cards are positioned on the card-holder unit with the active faces of both cards facing downwardly. However, the upper card projects further forward than the lower card, so a row of contacts at the front end of the upper card are exposed.
In the system, the card-holder unit is designed so the lower compartment closely holds a MICROSIM card, while the upper compartment closely holds an MMC card. Each card has a diagonally-cut polarizing corner for assuring proper orientation of the card. Walls on the connector that engage the polarizing corner are not always on the card-holder unit, but one can lie on the connector body.
The connector body includes a molded plastic lower part that forms the first or lower card-engaging wall and that holds the first set of contacts. The connector body includes a separately molded second part that is mounted on the front end of the lower part and that holds the second set of contacts at a higher elevation than the elevation of the first set of contacts.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.